For one strange moment, it looked as if the US Capitol building had been invaded by Vikings. Naked from the waist up, daubed with war paint and wearing a furry cowl with two curving horns, a protester posed for photographs in the chair where Vice President Mike Pence had sat
How extremist movements born on social media seized the heart of American Govt
"What we saw today was the by-product of weeks and probably months of escalating rhetoric within radical pro-Trump online communities," says Jared Holt, a visiting fellow at the Atlantic Council's "digital forensics" lab who monitors the online activity of America's domestic militia and paramilitary groups.
"A lot of the rhetoric being used in these communities was coming out of the mouth of protesters today, and then eventually influenced and [was] embodied [in] the insurrection against the US Capitol Building," he continues.
"These communities have been organising specifically around January 6 events in Washington, DC. When Trump put out the call for a 'wild protest', a lot of these groups we observe interpreted that call as a personal call to arms...
"All of this was discussed and playing out in the open for anybody who's paying attention to see."
Renee DiResta, a researcher at the Stanford Internet Observatory who has long warned about the consequences of social media algorithms, told the New York Times: "This has been a striking repudiation of the idea that there is an online and an offline world, and that what is said online is in some way kept online."
Protests across the country had been planned for about two weeks, spreading through the wide pool of Americans who believe Trump's claims of a stolen election.
January 6 was a natural date because it was when the US Senate would ceremonially confirm the election results. It was also when, according to the most recent QAnon lore, Vice President Mike Pence and Republican Senators would shock the nation by overturning the vote.
On December 27, a tweet by QAnon doyen General Mike Flynn calling for a march on Washington DC and satellite marches in state capitals was posted in pro-Trump Facebook groups. Later, on January 5, joyful videos and images on Instagram showed supporters driving in huge convoys or packing into planes to Washington.
On mainstream social networks, such discussions seen by The Telegraph rarely involved calls for violence. But on smaller fringe services, seasoned extremist groups plotted to use the protests as a springboard for civil war.
One key venue was a splinter site created by exiles from a now-banned Reddit community. "What if Congress ignores the evidence?" asked a post seen by Buzzfeed. "Storm the Capitol," said a popular reply. "Armed with rifle, handgun, two knives and as much ammo as you can carry," another user wrote.
A post on Dec 30 read: "I'm thinking it will be literal war on that day. Where we'll storm offices and physically remove and even kill all the DC traitors and reclaim the country."
Another small service, roughly similar to Facebook, hosted a call to "shoot anyone you see wearing a Maga hat on backward", quoting a tweet that claimed Left-wing infiltrators would identify themselves in that manner.
Not that Facebook was entirely peaceful. A pro-Trump group called Red State Secession, with just under 8,000 followers, asked users to gather information about "the addresses and residences of our political enemies in DC", as well as "their routes to and from" the Senate ceremony. The group now appears to have been deleted.
"You had intense buy-in from the militia movement that came into DC," says Holt, describing what he saw across multiple social networks. "In the run-up to it, users were sharing maps of the US Capitol; they were advising one another on how to potentially overwhelm police so that they could violate laws and enter federal buildings.
"I observed, on several occasions, people who were planning to attend the protests in DC sharing maps that contained entry points – even tunnels that exist beneath the Capitol – and were encouraging one another to breach security and enter the Capitol building to make a statement."
These discussions were rarely part of some grand plan. Various factions produced their own conflicting plans for the big day, with furious debates over whether to attend incognito or openly carry guns in defiance of Washington DC law.
In examples seen by The Telegraph, calls or preparations for violence, and ideas for storming the Capitol, often arose spontaneously during back-and-forth conversations.
"Where a lot of these discussions were happening is in the comments between users," says Holt. "There were a handful of influencers that were suggesting this idea in vague terms, but where people were really working each other up was in the comment sections, or the group chats affiliated with groups.
"This was kind of an undercurrent that was brewing beneath the larger events of the day."
He described a spectrum of goals and motivations even among militia groups, with some simply hoping to send a message, others wanting to stop the certification of results and others who were intent on bloodshed.
During the protest, appalled observers and journalists on Twitter circulated a photograph of a masked man climbing through one of the Capitol's public galleries with a bundle of plastic zip ties, which was interpreted as a sign that he meant to take hostages.
Live streamers also played an important role. Having fired up viewers before the storming, they then broadcast the action with varying levels of support. While some acted as neutral reporters, others were participants, encouraging the people around them to play to the cameras.
By the end of Wednesday the crisis was severe enough to finally push Facebook and Twitter into unprecedented measures. Both temporarily banned President Trump from posting, and permanent ejection remains on the table; Facebook also banned all images and video shared by protesters.
Mark Zuckerberg, Facebook's chief executive, condemned the violence, telling employees: "This is a dark moment in our nation's history... I'm personally saddened by this mob violence, which is exactly what this is."
Both Facebook's and Twitter's approach to disinformation and extremist movements has been transformed in the crucible of the pandemic, with steadily harsher crackdowns throughout the second half of 2020.
Yet Renee DiResta argues that those bigger social networks are partly responsible for bringing the country to this point in the first place. For years, researchers and journalists have documented how they create a scramble for attention and popularity that rewards certain kinds of activism or speech while punishing others.
Movements such as QAnon have prospered in that ecosystem. At times, tech firms' algorithms appear to have acted as recruiting sergeants, learning what kinds of people were already interested in radical messages and then pushing them out to similar users on a massive scale.
Although DiResta lays much of the blame with President Trump and his allies, who have spent months pushing groundless and ever-shifting claims that the election was being stolen, she says:
"There were several different factions of Trump supporters present at the protest today. The more conspiratorial among them, such as QAnon, grew as a uniquely online movement.
"Over a period of two years this community expanded, and for a period of time some of their online groups were actively recommended to other users via platform recommendation engines.
"Although Facebook and others took action on that particular community in 2020, it had significant cohesion and it has migrated to other platforms. At this point, banning and moderating won't remove the demand for the content, or reduce the belief."
- Telegraph Media Group